The present invention provides a cap cooler for a steel
plant using high-temperature R515B
refrigerant, comprising a cabin with an
evaporator located on the upper part of a ceiling crane in a steel
plant and an outdoor unit with a condenser located thereon; wherein the
refrigerant of the
refrigerant system formed by the
evaporator and condenser is R515B; wherein the
discharge refrigerant of the compressor forming the refrigerant
system passes through an oil separator, passes through the condenser of the outdoor unit, passes through a
receiver, passes through a filter dryer, passes through a
sight glass, and a portion of the liquid refrigerant is branched, passes through a
solenoid valve and an injection to spray the liquid refrigerant, thereby cooling the motor inside the compressor, converting it into a gaseous refrigerant, and then being drawn back into the compressor; and the remaining refrigerant is supplied to an
electronic expansion valve, converting it into a low-temperature, low-pressure refrigerant, passing through the
evaporator inside the cabin, thereby creating a comfortable air environment for the worker. This is because the
evaporation temperatures of R22 and R410a, which are widely used as air conditioner refrigerants, are not suitable for the ambient conditions where the
air temperature of a steel
plant is approximately 100°C, but since the present invention uses the refrigerant R515B, which has a relatively high
condensation temperature, it has a favorable effect on the air environment of the cabin room of a steel plant. In addition, by adopting R515B refrigerant and adding an injection function to address the problem of
subcooling on the evaporator outlet side that may occur, the liquid refrigerant in the compressor suction side is converted into gaseous refrigerant, thereby increasing the efficiency of the refrigerant cycle. In addition, to solve the problem where the efficiency of the refrigerant cycle is reduced and the
evaporation and condensation temperatures of the refrigerant cycle become unstable due to excessive
air temperature conditions inside the
steel mill, an
electronic expansion valve is connected to the
control unit to stabilize the unstable
evaporation and condensation temperatures, and the operation is controlled to correspond to preset evaporation and condensation temperatures.